Improving Security of the Crypto-Stego Approach using Time Sequence Dictionary and Spacing Modification Techniques

  • Eman S. Harba Avicenna Unit for E-Learning, College of Arts, University of Baghdad, Baghdad, Iraq
  • Hind S. Harba Department of Atmospheric Sciences, College of Science, University of Mustansiriyah, Baghdad, Iraq
  • Inas Ali Abdulmunem Department of Computer science, College of Science University of Baghdad, Baghdad, Iraq
  • Samera Shams Hussein Department of Computer Science, College of Education for pure Science, University of Baghdad, Baghdad, Iraq
Keywords: AES, Cryptography, Steganography, Text Stego., Time Sequence

Abstract

Cryptography steganography is a practical tool for data security. Hybridization of the cryptography with steganography can provide more security by taking advantage of each technique. This work proposes a method for improving the crypto-stego method by utilizing the proposed dictionary method to modified ciphertext. After that, the modified encrypt ciphertext id was hidden in the text by using the proposed method. For cryptography, an Advanced Encryption Standard (AES) was utilized to encrypt the message. The AES employed a 128bit block size and 256bit key size. The ciphertext characters were then replaced by the characters identified by a dictionary list. The dictionary is time-dependent, where each of the equivalent words shift based on the time-shift equation. The modified ciphertext was then embedded into a cover text so that the attacker cannot separate them by applying cryptanalysis.  The "Modifying Spain" method used the "Space" to build a steganography tool that hides the secret message.

The simulation results show that the proposed method achieved a high-security level when the cryptography and steganography are combined in such a way that the ciphertext is changed to another value by using a dictionary with a time sequence that makes the cryptanalysis test fails to guess and identify the algorithm that has been used for encryption. The stego test shows that the proposed method achieved good results in terms of capacity and visibility, being proved to be hard to notice. The tests also prove that the proposed method runs fast with less computational requirements.

Published
2021-05-31
How to Cite
Harba , E. S., Harba, H. S., Abdulmunem, I. A., & Hussein, S. S. (2021). Improving Security of the Crypto-Stego Approach using Time Sequence Dictionary and Spacing Modification Techniques. Iraqi Journal of Science, 62(5). https://doi.org/10.24996/10.24996/ijs.2021.62.5.35
Section
Computer Science